A four channel data acquisition system is developed to study somatosensory evoked potentials in the normal subjects and scoliotic patients. The somatosensory evoke potentials are of micro volts range and are extracted from noise, by averaging the responses obtained after multiple electrical stimulations. The electrical stimulations and data acquisition are carried out in synchronization and their parameters are controlled by a computer. The system have advantages like cost effectiveness, high sensitivity two signals and ability to record low amplitude complex patterns over existing data acquisition systems.